Rep. Charlie Rangel’s unofficial lead in the congressional primary over state Sen. Adriano Espaillat has dipped to a scant 802 votes — 18,075 to Espaillat’s 17,273 — the City Board of Elections said last night.

On election night last Tuesday, Rangel was reportedly leading by 6 percentage points. Now, as the slow counting of the votes continues, the 21-term congressman is leading by less than 2 points.

And there’s still more counting to do, as about 2,000 paper ballot votes are due to be tallied starting this week.

Officials said some absentee ballots may also still come in — so that number could change further.

Espaillat would need to capture close to 70 percent of the paper votes to win — which is unlikely.

Still, sources within the Rangel camp are admitting privately that the congressman’s margin of victory will be even thinner than the 802-vote margin announced last night.

The diminishing lead left Espaillat hopeful, but not enough for the Dominican-born candidate to rescind the concession speech he delivered on Election Night.

Several largely Hispanic districts in The Bronx reported zero votes cast on initial tallies Tuesday night, leading Espaillat’s camp to question the results.

Board spokeswoman Valerie Vazquez attributed that to poll workers’ handwriting and the way that police who handle the ballots sometimes transcribe results.

Ending the drama is important to Espaillat on more than one front. There is speculation that he might run again for his Senate seat if he loses to Rangel — and he’d have to get that campaign going within the next couple of weeks.